From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754872AbcA2IyU (ORCPT ); Fri, 29 Jan 2016 03:54:20 -0500 Received: from h2.hallyn.com ([78.46.35.8]:43925 "EHLO h2.hallyn.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753331AbcA2IyP (ORCPT ); Fri, 29 Jan 2016 03:54:15 -0500 From: serge.hallyn@ubuntu.com To: linux-kernel@vger.kernel.org Cc: adityakali@google.com, tj@kernel.org, linux-api@vger.kernel.org, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, lxc-devel@lists.linuxcontainers.org, akpm@linux-foundation.org, ebiederm@xmission.com, gregkh@linuxfoundation.org, lizefan@huawei.com, hannes@cmpxchg.org, "Serge E. Hallyn" Subject: [PATCH 4/8] cgroup: cgroup namespace setns support Date: Fri, 29 Jan 2016 02:54:07 -0600 Message-Id: <1454057651-23959-5-git-send-email-serge.hallyn@ubuntu.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1454057651-23959-1-git-send-email-serge.hallyn@ubuntu.com> References: <1454057651-23959-1-git-send-email-serge.hallyn@ubuntu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Aditya Kali setns on a cgroup namespace is allowed only if task has CAP_SYS_ADMIN in its current user-namespace and over the user-namespace associated with target cgroupns. No implicit cgroup changes happen with attaching to another cgroupns. It is expected that the somone moves the attaching process under the target cgroupns-root. Signed-off-by: Aditya Kali Signed-off-by: Serge E. Hallyn --- kernel/cgroup.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index d828e1f..96e3dab 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -6004,10 +6004,23 @@ static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns) return container_of(ns, struct cgroup_namespace, ns); } -static int cgroupns_install(struct nsproxy *nsproxy, void *ns) +static int cgroupns_install(struct nsproxy *nsproxy, struct ns_common *ns) { - pr_info("setns not supported for cgroup namespace"); - return -EINVAL; + struct cgroup_namespace *cgroup_ns = to_cg_ns(ns); + + if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN) || + !ns_capable(cgroup_ns->user_ns, CAP_SYS_ADMIN)) + return -EPERM; + + /* Don't need to do anything if we are attaching to our own cgroupns. */ + if (cgroup_ns == nsproxy->cgroup_ns) + return 0; + + get_cgroup_ns(cgroup_ns); + put_cgroup_ns(nsproxy->cgroup_ns); + nsproxy->cgroup_ns = cgroup_ns; + + return 0; } static struct ns_common *cgroupns_get(struct task_struct *task) -- 1.7.9.5